U.S. patent application number 16/442831 was filed with the patent office on 2019-12-19 for liquid discharge head, liquid discharge apparatus, and wiring substrate.
The applicant listed for this patent is Seiko Epson Corporation. Invention is credited to Eiju HIRAI, Shingo TOMIMATSU, Daisuke YAMADA.
Application Number | 20190381796 16/442831 |
Document ID | / |
Family ID | 68839102 |
Filed Date | 2019-12-19 |
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United States Patent
Application |
20190381796 |
Kind Code |
A1 |
HIRAI; Eiju ; et
al. |
December 19, 2019 |
Liquid Discharge Head, Liquid Discharge Apparatus, And Wiring
Substrate
Abstract
There is provided a liquid discharge head including a first
wiring through which a drive signal is input to a wiring substrate,
in which the wiring substrate has a substrate having a first
surface and a second surface that opposes the first surface, a
second wiring formed on the first surface, a third wiring formed on
the second surface, a fourth wiring and a fifth wiring that pass
through the substrate and electrically couples the second wiring
with the third wiring, and an electrode provided on the second
wiring and electrically couples the second wiring with the first
wiring, and the electrode is positioned between a first coupling
point at which the fourth wiring is electrically coupled to the
second wiring and a second coupling point at which the fifth wiring
is electrically coupled to the second wiring, in the second
wiring.
Inventors: |
HIRAI; Eiju; (Azumino,
JP) ; YAMADA; Daisuke; (Shiojiri, JP) ;
TOMIMATSU; Shingo; (Matsumoto, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Seiko Epson Corporation |
Tokyo |
|
JP |
|
|
Family ID: |
68839102 |
Appl. No.: |
16/442831 |
Filed: |
June 17, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B41J 2/04581 20130101;
B41J 2002/14491 20130101; B41J 2202/18 20130101; B41J 2002/14241
20130101; B41J 2/04593 20130101; B41J 2/04596 20130101; B41J
2002/14362 20130101; B41J 2202/13 20130101; B41J 2/04588 20130101;
B41J 2/14233 20130101; B41J 2002/14419 20130101 |
International
Class: |
B41J 2/14 20060101
B41J002/14 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 18, 2018 |
JP |
2018-115272 |
Claims
1. A liquid discharge head comprising: a drive element driven by a
drive signal supplied thereto; an actuator substrate provided with
the drive element; a drive IC that controls a supply of the drive
signal to the drive element; a wiring substrate that propagates the
drive signal to the drive IC; and a first wiring through which the
drive signal is input to the wiring substrate, wherein the wiring
substrate has a substrate having a first surface and a second
surface that opposes the first surface, a second wiring formed on
the first surface, a third wiring formed on the second surface, a
fourth wiring and a fifth wiring that pass through the substrate
and electrically couple the second wiring with the third wiring,
and an electrode provided on the second wiring and electrically
couples the second wiring with the first wiring, and in the second
wiring, the electrode is positioned between a first coupling point
at which the fourth wiring is electrically coupled to the second
wiring and a second coupling point at which the fifth wiring is
electrically coupled to the second wiring.
2. The liquid discharge head according to claim 1, wherein the
substrate has a first side and a second side longer than the first
side, and the electrode is provided between the fourth wiring and
the fifth wiring in a direction along the second side.
3. The liquid discharge head according to claim 1, wherein the
drive IC is provided on the wiring substrate, and the electrode is
provided between the fourth wiring and the drive IC.
4. The liquid discharge head according to claim 3, wherein the
substrate has a first side and a second side longer than the first
side, and the electrode is provided between the fourth wiring and
the drive IC in a direction along the second side.
5. The liquid discharge head according to claim 1, wherein the
second wiring includes a first buried wiring buried in the
substrate, the third wiring includes a second buried wiring buried
in the substrate, and when viewed from the first surface, a part of
the first buried wiring overlaps with the electrode and a part of
the second buried wiring overlaps with the electrode.
6. The liquid discharge head according to claim 1, wherein the
wiring substrate includes a sixth wiring passing through the
substrate and electrically coupling the second wiring with the
third wiring, and a third coupling point at which the sixth wiring
is electrically coupled to the second wiring, and in the second
wiring, the third coupling point is positioned between the
electrode and the second coupling point.
7. A liquid discharge apparatus comprising: the liquid discharge
head according to claim 1; and a drive circuit that outputs the
drive signal.
8. A wiring substrate provided in a liquid discharge head including
a drive element driven by a drive signal supplied thereto, an
actuator substrate provided with the drive element, a drive IC that
controls a supply of the drive signal to the drive element, and a
first wiring through which the drive signal is input, the wiring
substrate comprising: a substrate having a first surface and a
second surface that opposes the first surface; a second wiring
formed on the first surface; a third wiring formed on the second
surface; a fourth wiring and a fifth wiring passing through the
substrate and electrically coupling the second wiring with the
third wiring; and an electrode provided on the second wiring and
electrically coupling the second wiring with the first wiring,
wherein in the second wiring, the electrode is positioned between a
first coupling point at which the fourth wiring is electrically
coupled to the second wiring and a second coupling point at which
the fifth wiring is electrically coupled to the second wiring.
Description
[0001] The present application is based on, and claims priority
from, JP Application Serial Number 2018-115272, filed Jun. 18,
2018, the disclosure of which is hereby incorporated by reference
herein in its entirety.
BACKGROUND
1. Technical Field
[0002] The present disclosure relates to a liquid discharge head, a
liquid discharge apparatus, and a wiring substrate.
2. Related Art
[0003] A liquid discharge apparatus such as an ink jet printer
discharges a liquid such as ink filled in a cavity from nozzles by
driving a drive element such as a piezoelectric element provided in
a liquid discharge head by a drive signal to form characters and
images on a recording medium. In such a liquid discharge head, in
order to miniaturize the liquid discharge head, there is a
structure in which a drive IC for outputting a drive signal input
to the liquid discharge head based on a control signal input to the
liquid discharge head likewise, is mounted on an actuator substrate
on which a piezoelectric element is provided.
[0004] For example, JP-A-2017-168748 discloses a technology in
which a drive IC is mounted on an actuator substrate via an
interposer substrate (wiring substrate), and wirings through which
drive signals are propagated are formed on both sides of the drive
IC side of the wiring substrate and the actuator substrate
side.
[0005] However, with the technology described in JP-A-2017-168748,
there is a possibility that it becomes difficult to sufficiently
reduce a wiring resistance occurring on the wiring substrate.
[0006] In order to respond to recent high-definition printing
requirements, the number of nozzles formed in a liquid discharge
head is increased, so that current propagated in a wiring substrate
increases. In such a case, deterioration of drive signals
propagated on the wiring substrate and heat generation of the
wiring substrate may increase due to the wiring resistance
occurring on the wiring substrate.
SUMMARY
[0007] According to an aspect of the present disclosure, there is
provided a liquid discharge head including a drive element driven
by a drive signal supplied thereto; an actuator substrate provided
with the drive element; a drive IC that controls a supply of the
drive signal to the drive element; a wiring substrate that
propagates the drive signal to the drive IC; and a first wiring
through which the drive signal is input to the wiring substrate, in
which the wiring substrate has a substrate having a first surface
and a second surface that opposes the first surface, a second
wiring formed on the first surface, a third wiring formed on the
second surface, a fourth wiring and a fifth wiring that pass
through the substrate and electrically couple the second wiring
with the third wiring, and an electrode provided on the second
wiring and electrically couples the second wiring with the first
wiring, and the electrode is positioned between a first coupling
point at which the fourth wiring is electrically coupled to the
second wiring and a second coupling point at which the fifth wiring
is electrically coupled to the second wiring, in the second
wiring.
[0008] In the liquid discharge head, the substrate may have a first
side and a second side longer than the first side, and the
electrode may be provided between the fourth wiring and the fifth
wiring in a direction along the second side.
[0009] In the liquid discharge head, the drive IC may be provided
on the wiring substrate, and the electrode may be provided between
the fourth wiring and the drive IC.
[0010] In the liquid discharge head, the substrate may have a first
side and a second side longer than the first side, and the
electrode may be provided between the fourth wiring and the drive
IC in a direction along the second side.
[0011] In the liquid discharge head, the second wiring may include
a first buried wiring buried in the substrate, the third wiring may
include a second buried wiring buried in the substrate, and when
viewed from the first surface, a part of the first buried wiring
may overlap with the electrode and a part of the second buried
wiring may overlap with the electrode.
[0012] In the liquid discharge head, the wiring substrate may
include a sixth wiring passing through the substrate and
electrically coupling the second wiring with the third wiring, and
a third coupling point at which the sixth wiring is electrically
coupled to the second wiring, and the third coupling point may be
positioned between the electrode and the second coupling point in
the second wiring.
[0013] According to another aspect of the present disclosure, there
is provided a liquid discharge apparatus including the aspect of
the liquid discharge head and a drive circuit that outputs the
drive signal.
[0014] According to still another aspect of the present disclosure,
there is provided a wiring substrate provided in a liquid discharge
head including a drive element driven by a drive signal supplied
thereto, an actuator substrate provided with the drive element, a
drive IC that controls a supply of the drive signal to the drive
element, and a first wiring through which the drive signal is
input, the wiring substrate including a substrate having a first
surface and a second surface that opposes the first surface; a
second wiring formed on the first surface; a third wiring formed on
the second surface; a fourth wiring and a fifth wiring passing
through the substrate and electrically coupling the second wiring
with the third wiring; and an electrode provided on the second
wiring and electrically coupling the second wiring with the first
wiring, in which the electrode is positioned between a first
coupling point at which the fourth wiring is electrically coupled
to the second wiring and a second coupling point at which the fifth
wiring is electrically coupled to the second wiring, in the second
wiring.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a diagram showing a schematic configuration of a
liquid discharge apparatus.
[0016] FIG. 2 is a block diagram showing an electrical
configuration of the liquid discharge apparatus.
[0017] FIG. 3 is a disassembled perspective view of a liquid
discharge head.
[0018] FIG. 4 is a cross-sectional view showing a cross section of
the liquid discharge head taken along line IV-IV in FIG. 3.
[0019] FIG. 5 is a diagram showing an example of drive signals.
[0020] FIG. 6 is a diagram for explaining electrical couplings of a
drive IC, a wiring substrate, an actuator substrate, and
piezoelectric elements.
[0021] FIG. 7 is a diagram showing an example of a configuration of
a bump electrode.
[0022] FIG. 8 is a diagram showing a configuration when the wiring
substrate is viewed from a surface.
[0023] FIG. 9 is a diagram showing a configuration when the wiring
substrate is viewed from a surface.
[0024] FIG. 10 is a diagram showing a configuration when a wiring
substrate of a second embodiment is viewed from a surface.
[0025] FIG. 11 is a diagram showing a configuration when the wiring
substrate of the second embodiment is viewed from a surface.
[0026] FIG. 12 is a diagram showing a configuration when a wiring
substrate of a third embodiment is viewed from a surface.
[0027] FIG. 13 is a diagram showing a configuration when the wiring
substrate of the third embodiment is viewed from a surface.
[0028] FIG. 14 is a diagram showing a configuration when a wiring
substrate of a fourth embodiment is viewed from a surface.
[0029] FIG. 15 is a diagram showing a configuration when the wiring
substrate of the fourth embodiment is viewed from a surface.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0030] Hereinafter, preferred embodiments of the present disclosure
will be described with reference to the drawings. The drawings used
are for convenience of explanation. Note that, the embodiments
described below do not unreasonably limit the contents of the
present disclosure described in the claims. In addition, all of the
configurations described below are not necessarily indispensable
constitutional requirements of the present disclosure.
[0031] Hereinafter, a liquid discharge head provided with a wiring
substrate according to the present disclosure will be described by
taking a liquid discharge head applied to a liquid discharge
apparatus as a printing apparatus, as an example.
1 First Embodiment
1.1 Outline of Liquid Discharge Apparatus
[0032] FIG. 1 is a diagram showing a schematic configuration of a
liquid discharge apparatus 1 to which a liquid discharge head of
the present embodiment is applied. The liquid discharge apparatus 1
according to the present embodiment is a serial printing type ink
jet printer where a carriage 22, on which liquid discharge heads 21
for discharging ink as an example of a liquid are mounted,
reciprocates and ink is discharged onto a medium P to be
transported. In the following description, it is assumed that an
axis in which the carriage 22 moves is a X axis, a direction in
which the medium P is transported is a Y direction, and a direction
in which the ink is discharged is a Z direction. Note that in the
following description, it is assumed that the X axis, the Y
direction and the Z direction are orthogonal to each other. As the
medium P, any printing target such as a printing paper, a resin
film, and a cloth may be used.
[0033] The liquid discharge apparatus 1 includes a liquid container
2, a control unit 10, a head unit 20, a moving unit 80, and a
transport unit 70.
[0034] In the liquid container 2, a plurality of kinds of inks to
be discharged onto the medium P are stored. Specifically, six types
of inks of black, cyan, magenta, yellow, red, and gray are stored
in the liquid container 2. The number and types of inks stored in
the liquid container 2 is merely an example, and the number of inks
stored in the liquid container 2 may be five or less, or may be
seven or more. Furthermore, inks of colors such as light cyan,
light magenta, green may be stored in the liquid container 2. As
the liquid container 2 in which such inks are stored, an ink
cartridge, a bag-shaped ink pack formed of a flexible film, an ink
tank capable of replenishing ink, or the like are used.
[0035] The control unit 10 includes a processing circuit such as a
central processing unit (CPU), a field programmable gate array
(FPGA), or the like and a memory circuit such as a semiconductor
memory, and controls each element of the liquid discharge apparatus
1.
[0036] The head unit 20 includes the liquid discharge heads 21 and
the carriage 22. The liquid discharge heads 21 are mounted on the
carriage 22. The carriage 22 is fixed to an endless belt 82
included in the moving unit 80 in a state where the liquid
discharge heads 21 are mounted. Note that the liquid container 2
may also be mounted on the carriage 22. Further, control signals
Ctrl-H including a plurality of signals for controlling the liquid
discharge heads 21 and one or a plurality of drive signals COM for
driving the liquid discharge heads 21 are input from the control
unit 10 to the liquid discharge heads 21. The liquid discharge
heads 21 discharge ink supplied from the liquid container 2 in the
Z direction based on the control signals Ctrl-H and one or more
drive signals COM.
[0037] The moving unit 80 includes a carriage motor 81 and the
endless belt 82. The carriage motor 81 operates based on a control
signal Ctrl-C input from the control unit 10. The endless belt 82
pivots in accordance with an operation of the carriage motor 81. In
this way, the carriage 22 fixed to the endless belt 82 reciprocates
in the X axis.
[0038] The transport unit 70 includes a transport motor 71 and
transport rollers 72. The transport motor 71 operates based on a
control signal Ctrl-T input from the control unit 10. Then, the
transport rollers 72 pivot according to an operation of the
transport motor 71. The medium P is transported in the Y direction
according to the pivot of the transport rollers 72.
[0039] As described above, the liquid discharge apparatus 1 causes
ink to land at any position on a surface of the medium P to form a
desired image on the medium P by discharging the ink from the
liquid discharge heads 21 included in the head unit 20 in
conjunction with the transport of the medium P by the transport
unit 70 and the reciprocation of the head unit 20 by the moving
unit 80 based on various signals output from the control unit
10.
1.2 Electrical Configuration of Liquid Discharge Apparatus
[0040] FIG. 2 is a block diagram showing an electrical
configuration of the liquid discharge apparatus 1. The liquid
discharge apparatus 1 includes the control unit 10, the head unit
20, the moving unit 80, and the transport unit 70. As shown in FIG.
2, the control unit 10 includes a control circuit 100, drive
circuits 50a and 50b, a reference voltage generation circuit 51,
and a power supply voltage generation circuit 53.
[0041] The control circuit 100 includes, for example, a processor
such as a microcontroller. The control circuit 100 generates data
or signals for controlling the liquid discharge apparatus 1 based
on various signals such as image data supplied from a host
computer.
[0042] Specifically, the control circuit 100 outputs the control
signal Ctrl-C corresponding to a scanning position of the head unit
20 to the moving unit 80. Thus, the reciprocation of the head unit
20 is controlled. Further, the control circuit 100 outputs the
control signal Ctrl-T to the transport unit 70. Consequently, the
transportation of the medium P is controlled. Note that the control
signal Ctrl-C may be supplied to the moving unit 80 after a signal
conversion by a signal conversion circuit (not shown). Note that
the control signal Ctrl-T may be supplied to the transport unit 70
after a signal conversion by the signal conversion circuit (not
shown).
[0043] In addition, the control circuit 100 outputs a printing data
signal SI, a change signal CH, a latch signal LAT, and a clock
signal SCK as the control signal Ctrl-H for controlling the head
unit 20 based on various signals such as image data supplied from
the host computer.
[0044] Further, the control circuit 100 outputs drive control
signals dA and dB which are digital signals of the drive circuits
50a and 50b, respectively.
[0045] Specifically, the drive control signal dA is input to the
drive circuit 50a. The drive circuit 50a performs digital/analog
conversion on the drive control signal dA, and then class-D
amplifies the converted analog signal to generate the drive signal
COMA. The drive circuit 50a outputs the generated drive signal COMA
to the head unit 20. Further, the drive control signal dB is input
to the drive circuit 50b. The drive circuit 50b performs
digital/analog conversion on the drive control signal dB, and then
class-D amplifies the converted analog signal to generate the drive
signal COMB. The drive circuit 50b outputs the generated drive
signal COMB to the head unit 20.
[0046] The reference voltage generation circuit 51 generates a
reference voltage signal VBS supplied to piezoelectric elements 60
included in the head unit 20. The reference voltage signal VBS is,
for example, a voltage signal of DC 6 V. Then, the reference
voltage generation circuit 51 outputs the generated reference
voltage signal VBS to the head unit 20. Note that the reference
voltage generation circuit 51 may generate and output a voltage
signal of a different voltage value other than DC 6 V.
[0047] The power supply voltage generation circuit 53 generates a
high voltage signal VHV and a low voltage signal VDD. The high
voltage signal VHV is, for example, a voltage signal of DC 42 V.
The low voltage signal VDD is, for example, a voltage signal of
3.3V. Each of the high voltage signal VHV and the low voltage
signal VDD is used as a power supply voltage of various
configurations in the control unit 10 and is also output to the
head unit 20. Note that the power supply voltage generation circuit
53 may generate various voltage signals other than the high voltage
signal VHV and the low voltage signal VDD.
[0048] The head unit 20 includes a plurality of liquid discharge
heads 21. The print data signal SI, the change signal CH, the latch
signal LAT, the clock signal SCK, the drive signals COMA and COMB,
the reference voltage signal VBS, the high voltage signal VHV and
the low voltage signal VDD, which are input to the head unit 20,
are branched in the head unit 20 and then supplied to each of the
plurality of liquid discharge heads 21. Note that each of the
plurality of liquid discharge heads 21 has the same
configuration.
[0049] Each liquid discharge head 21 includes a drive signal
selection circuit 200 and a plurality of discharge units 600. The
drive signal selection circuit 200 generates drive signals VOUT by
selecting or deselecting the drive signals COMA and COMB based on
the input signals such as print data signal SI, the clock signal
SCK, the latch signal LAT and the change signal CH. Then, the drive
signal selection circuit 200 supplies the drive signal VOUT to the
piezoelectric element included in the corresponding discharge unit
600. The piezoelectric element 60 is displaced when the drive
signal VOUT is supplied. Then the amount of ink according to the
displacement is discharged from the discharge unit 600. That is,
the piezoelectric element 60 driven by the drive signal VOUT
supplied thereto based on the drive signals COMA and COMB, is an
example of a drive element.
1.3 Configuration of Liquid Discharge Head
[0050] A configuration of the liquid discharge head 21 will be
described. FIG. 3 is a disassembled perspective view of a liquid
discharge head 21. FIG. 4 is a cross-sectional view showing a cross
section of the liquid discharge head 21 taken along the line IV-IV
in FIG. 3.
[0051] As shown in FIG. 3, the liquid discharge head 21 includes 2M
number of nozzles N arranged in the Y direction. In the present
embodiment, 2M number nozzles N are arranged in two lines of a line
L1 and a line L2. In the following description, each of the M
number of nozzles N belonging to the line L1 will be referred to as
nozzles N1, and each of the M number of nozzles N belonging to the
line L2 will be referred to as nozzles N2. Further, in the
following description, a case in which positions of a m-th (m is a
natural number satisfying 1.ltoreq.m.ltoreq.M) nozzle N1 among the
M number of nozzles N1 belonging to the line L1 and a m-th nozzle
N2 among the M number of nozzles N2 belonging to the line L2
substantially coincide in the Y direction, is assumed. Here,
"substantially coincide" includes not only cases where the
positions are perfectly matched but also cases where the positions
can be regarded as identical if margin of errors are considered.
Note that 2M number of nozzles N may be arranged in so-called, a
zigzag shape or a staggered shape, so that the position in the Y
direction between the positions of the m-th nozzle N1 among the M
number of nozzles N1 belonging to the line L1 and the m-th nozzle
N2 among the M number of nozzles N2 belonging to the line L2 are
different.
[0052] As shown in FIGS. 3 and 4, the liquid discharge head 21
includes a flow channel substrate 32. The flow channel substrate 32
is a plate-shaped member including a surface F1 and a surface FA.
The surface F1 is a surface on the side of the medium P as viewed
from the liquid discharge head 21, and the surface FA is a surface
on the side opposite to the surface F1. On top of the surface of
the surface FA, a pressure chamber substrate 34, an actuator
substrate 36, a plurality of piezoelectric elements 60, a wiring
substrate 38, and a housing portion 40 are provided. On top of the
surface of the surface F1, a nozzle plate 52 and a vibration
absorber 54 are provided. Each element of the liquid discharge head
21 is roughly a plate-shaped member elongated in the Y direction,
and is stacked in the Z direction.
[0053] The nozzle plate 52 is a plate-shaped member, and 2M number
of nozzles N, which are through holes, are formed in the nozzle
plate 52. In the following description, 600 or more nozzles N are
formed on the nozzle plate 52, and the nozzles N corresponding to
each of the lines L1 and L2 are provided at a density of 300 or
more nozzles per inch.
[0054] The flow channel substrate 32 is a plate-shaped member for
forming a flow channel for ink. As shown in FIGS. 3 and 4, a flow
channel RA is formed on the flow channel substrate 32. Further, on
the flow channel substrate 32, 2M number of flow channels 31 and 2M
number of flow channels 33 are formed so as to correspond to 2M
number of nozzles N on a one-to-one basis. The flow channels 31 and
the flow channels 33 are opening ports formed so as to pass through
the flow channel substrate 32 as shown in FIG. 4. A flow channel 33
communicates with a nozzle N corresponding to the flow channel 33.
Further, on the surface F1 of the flow channel substrate 32, two
flow channels 39 are formed. One of the two flow channels 39 is a
flow channel that connects the flow channel RA and M number of flow
channels 31 corresponding one to one to the M number of nozzles N1
belonging to the line L1, and the other is a flow channel that
connects the flow channel RA and M number of flow channels 31
corresponding one to one to the M number of nozzles N2 belonging to
the line L2.
[0055] As shown in FIGS. 3 and 4, the pressure chamber substrate 34
is a plate-shaped member in which 2M number of opening ports 37 are
formed so as to correspond to the 2M number of nozzles N in a
one-to-one correspondence. On a surface of the pressure chamber
substrate 34 opposite to the flow channel substrate 32, the
actuator substrate 36 is provided.
[0056] As shown in FIG. 4, the actuator substrate 36 and the
surface FA of the flow channel substrate 32 face each other with a
space inside each opening port 37. The space located between the
surface FA of the flow channel substrate 32 and the actuator
substrate 36 inside the opening port 37 functions as a pressure
chamber C for applying pressure to the ink filled in the space. The
pressure chamber C is, for example, a space having an X axis as a
longitudinal axis and a Y direction as a short axis. In the liquid
discharge head 21, 2M number of pressure chambers C are provided so
as to correspond to the 2M number of nozzles N on a one-to-one
basis. The pressure chamber C provided corresponding to the nozzle
N1 communicates with the flow channel RA via the flow channel 31
and the flow channel 39, and also communicates with the nozzle N1
via the flow channel 33. Further, the pressure chamber C provided
corresponding to the nozzle N2 communicates with the flow channel
RA via the flow channel 31 and the flow channel 39, and also
communicates with the nozzle N2 via the flow channel 33.
[0057] As shown in FIGS. 3 and 4, on top of the surface of the
actuator substrate 36 opposite to the pressure chamber C, 2M number
of piezoelectric elements 60 are provided so as to correspond to
the 2M number of pressure chambers C in a one-to-one basis. The
drive signal VOUT based on the drive signals COMA and COMB is
supplied to one end of the piezoelectric element 60, and the
reference voltage signal VBS is supplied to the other end. The
piezoelectric element 60 deforms (drives) in accordance with an
electric potential difference between the drive signal VOUT and the
reference voltage signal VBS. The actuator substrate 36 vibrates
interlockingly with the deformation of the piezoelectric element
60, and when the actuator substrate 36 vibrates, a pressure in the
pressure chamber C changes. As the pressure in the pressure chamber
C changes, the ink filled in the pressure chamber C is discharged
via the flow channel 33 and the nozzle N.
[0058] Note that the pressure chamber C, the flow channels 31 and
33, the nozzle N, the actuator substrate 36, and the piezoelectric
element 60 function as the discharge unit 600 for discharging the
ink filled in the pressure chamber C by driving the piezoelectric
element 60. That is, in the liquid discharge head 21, a plurality
of discharge units 600 are arranged in two lines along the Y
direction.
[0059] The wiring substrate 38 shown in FIGS. 3 and 4 has a surface
G1 and a surface G2 opposing the surface G1, and propagates drive
signals COMA and COMB to the drive IC 62. The wiring substrate 38
is a plate-shaped member for protecting the 2M number of
piezoelectric elements 60 formed on the actuator substrate 36, and
is provided on the surface of the actuator substrate 36 or the
surface of the pressure chamber substrate 34.
[0060] Two accommodation spaces 45 are formed on the surface G1 of
the wiring substrate 38, which is a surface on the side of the
medium P as viewed from the liquid discharge head 21. One of the
two accommodation spaces 45 is a space for accommodating M number
of piezoelectric elements 60 corresponding to the M number of
nozzles N1 and the other is a space for accommodating M number of
piezoelectric elements 60 corresponding to the M number of nozzles
N2. A height which is a width in a Z direction of the accommodation
space 45 is sufficiently large so that the piezoelectric element 60
and the wiring substrate 38 do not come into contact with each
other even when the piezoelectric element 60 is displaced.
[0061] The drive IC 62 is provided on the surface G2 of the wiring
substrate 38, which is a surface on the side opposite to the
surface G1. For example, the drive signal selection circuit 200
shown in FIG. 2 is mounted on the drive IC 62. The drive signals
COMA and COMB, the printing data signal SI, the change signal CH,
the latch signal LAT and the clock signal SCK input to the liquid
discharge head 21 are input to the drive IC 62. Then, based on the
printing data signal SI, the drive IC 62 generates and outputs a
drive signal VOUT by switching whether or not to supply the drive
signals COMA and COMB to each piezoelectric element 60. That is,
the drive IC 62 controls a supply of the drive signals COMA and
COMB to the piezoelectric element 60.
[0062] A plurality of wirings are provided on the wiring substrate
38 for propagating the drive signals COMA, COMB, and VOUT, the
print data signal SI, the change signal CH, the latch signal LAT
and the clock signal SCK. The drive signal VOUT output from the
drive IC 62 is supplied to the piezoelectric element 60 via the
wiring.
[0063] In addition, a coupling wiring 64 is electrically coupled to
the wiring substrate 38. The coupling wiring 64 is a member in
which a plurality of wirings for transferring a plurality of
signals input to the liquid discharge head 21 to the drive IC 62
are formed, and may be, for example, an flexible printed circuit
(FPC), an flexible flat cable (FFC), or the like. In other words,
the coupling wiring 64 inputs a plurality of signals including the
drive signals COMA and COMB to the wiring substrate 38. Details of
the plurality of wirings formed on the wiring substrate 38 will be
described later. The coupling wiring 64 is an example of a first
wiring.
[0064] An operation in which one of the drive signals COMA and COMB
is selected in the drive IC 62 and the drive signal VOUT is
generated, will be described. The drive IC 62 generates and outputs
the drive signal VOUT supplied to the piezoelectric element 60 by
selecting or deselecting the drive signals COMA and COMB based on
the printing data signal SI, the change signal CH, and the latch
signal LAT.
[0065] The latch signal LAT defines a printing cycle Ta, which is a
cycle for forming dots on the medium P. Specifically, a cycle from
a generation of the latch signal LAT to a next generation of the
latch signal LAT becomes the printing cycle Ta. Further, the change
signal CH divides the printing cycle Ta into a plurality of cycles
Tn (n is a positive integer). The printing data signal SI includes
data signals corresponding to each of a plurality of discharge
units 600, and selects or deselects each of the drive signals COMA
and COMB for each cycle Tn. In this way, the drive IC 62 generates
the drive signal VOUT in the printing cycle Ta by selecting or
deselecting each of the drive signals COMA and COMB for each cycle
Tn based on the printing data signal SI.
[0066] A generation procedure of the drive signal VOUT in the drive
IC 62 will be described by taking the drive signals COMA and COMB
shown in FIG. 5 as an example. Note that the printing cycle Ta in
FIG. 5 is configured with two cycles, which are a cycle T1 from a
generation of the latch signal LAT to a generation of the change
signal CH and a cycle T2 from a generation of the change signal CH
to a generation of the latch signal LAT.
[0067] The drive signal COMA is a signal configured with a waveform
in which a trapezoidal waveform Adp1 disposed in the cycle T1 and a
trapezoidal waveform Adp2 disposed in the cycle T2 are continuous.
The trapezoidal waveforms Adp1 and Adp2 have substantially the same
waveforms, and when each of the waveforms is supplied to one end of
the piezoelectric element 60, a moderate amount of ink is
discharged from the corresponding nozzle N of the discharge unit
600.
[0068] The drive signal COMB is a signal configured with a waveform
in which a trapezoidal waveform Bdp1 disposed in the cycle T1 and a
trapezoidal waveform Bdp2 disposed in the cycle T2 are continuous.
The trapezoidal waveforms Bdp1 and Bdp2 have different waveforms,
and among the waveforms, the trapezoidal waveform Bdp1 is a
waveform for slightly vibrating the ink in the vicinity of the
opening portion of the nozzle N to prevent viscosity of the ink
from increasing. Therefore, even if the trapezoidal waveform Bdp1
is supplied to one end of the piezoelectric element 60, an ink
droplet is not discharged from the corresponding nozzle N of the
discharge unit 600. The trapezoidal waveform Bdp2 is a waveform
different from that of both of the trapezoidal waveforms Adp1 and
Adp2, and when the trapezoidal waveform Bdp2 is supplied to one end
of the piezoelectric element 60, a small amount of ink less than
the moderate amount is discharged from the corresponding nozzle N
of the discharge unit 600.
[0069] Based on the printing data signal SI, the drive IC 62
generates the drive signal VOUT by controlling whether to supply
each of the drive signals COMA and COMB to each of the
piezoelectric elements 60 included in the plurality of discharge
units 600 in the cycle T1 and the cycle T2.
[0070] For example, when the printing data signal SI is a signal
indicating "large dot", the drive signal COMA is selected in the
cycles T1 and T2. As a result, the drive IC 62 outputs the drive
signal VOUT configured with a waveform in which the trapezoidal
waveform Adp1 and the trapezoidal waveform Adp2 are continuous in
the printing cycle Ta. At this time, a moderate amount of ink is
discharged twice from the nozzle N corresponding to the
piezoelectric element 60 to which the drive signal VOUT is
supplied. Therefore, a large dot is formed on the medium P.
[0071] Further, when the printing data signal SI is a signal
indicating "medium dot", the drive signal COMA is selected in the
cycle T1, and the drive signal COMB is selected in the cycle T2. As
a result, the drive IC 62 outputs the drive signal VOUT configured
with a waveform in which the trapezoidal waveform Adp1 and the
trapezoidal waveform Bdp2 are continuous in the printing cycle Ta.
At this time, a moderate amount of ink and a small amount of ink
are discharged from the nozzle N corresponding to the piezoelectric
element 60 to which the drive signal VOUT is supplied. Therefore, a
medium dot is formed on the medium P.
[0072] Further, when the printing data signal SI is a signal
indicating "small dot", neither the drive signals COMA and COMB are
selected in the cycle T1, and the drive signal COMB is selected in
the cycle T2. As a result, the drive IC 62 outputs the drive signal
VOUT configured with the trapezoidal waveform Bdp2 in the printing
cycle Ta. At this time, a small amount of ink is discharged from
the nozzle N corresponding to the piezoelectric element 60 to which
the drive signal VOUT is supplied. Therefore, a small dot is formed
on the medium P.
[0073] Further, when the printing data signal SI is a signal
indicating "micro vibration", the drive signal COMB is selected in
the cycle T1, and neither the drive signals COMA nor COMB are
selected in the cycle T2. As a result, the drive IC 62 outputs the
drive signal VOUT configured with the trapezoidal waveform Bdp1 in
the printing cycle Ta. At this time, the piezoelectric element 60
to which the drive signal VOUT is supplied is driven to such an
extent that the ink is not discharged, and the ink is not
discharged from the nozzle N corresponding to the piezoelectric
element 60. Therefore, a dot is not formed on the medium P.
[0074] A voltage at the start timing of the trapezoidal waveforms
Adp1, Adp2, Bdp1, and Bdp2 and a voltage at the end timing are
common to the voltage Vc. That is, each of the drive signals COMA
and COMB is configured with a waveform starting at the voltage Vc
and ending at the voltage Vc. Note that the drive signals COMA and
COMB shown in FIG. 5 are examples and are not limited thereto.
[0075] Returning to FIG. 3 and FIG. 4, a housing portion 40 is a
case for storing the ink supplied to the 2M number of pressure
chambers C. A surface FB of the casing portion 40, which is a
surface on the side of the medium P as viewed from the liquid
discharge head 21, is for example, fixed to the surface FA of the
flow channel substrate 32 with an adhesive. On the surface FB of
the casing portion 40, a groove-shaped concave portion 42 extending
in the Y direction is formed. The wiring substrate 38 and the drive
IC 62 are accommodated inside the concave portion 42. At this time,
the coupling wiring 64 is extended in the Y direction so as to pass
through inside of the concave portion 42.
[0076] The housing portion 40 is formed by, for example, injection
molding of a resin material. As shown in FIG. 4, a flow channel RB
communicating with the flow channel RA is formed in the housing
portion 40. The flow channel RA and the flow channel RB function as
a reservoir Q that stores the ink to be supplied to the 2M number
of pressure chambers C.
[0077] On the surface F2 which is a surface opposite to the surface
FB of the housing portion 40, two introducing ports 43 for
introducing the ink supplied from the liquid container 2 to the
reservoir Q, are provided. The ink supplied from the liquid
container 2 to the two introducing ports 43 flows into the flow
channel RA via the flow channel RB. A part of the ink flowed into
the flow channel RA is supplied to the pressure chamber C
corresponding to the nozzle N via the flow channel 39 and the flow
channel 31. The ink filled in the pressure chamber C corresponding
to the nozzle N is discharged from the nozzle N via the flow
channel 33 by driving the piezoelectric element 60 corresponding to
the nozzle N.
1.4 Configuration of Electrical Couplings of Drive IC, Wiring
Substrate and Actuator Substrate
[0078] Next, electrical couplings of the drive IC 62, the wiring
substrate 38, the actuator substrate 36, and the piezoelectric
element 60 will be described with reference to FIG. 6. FIG. 6 is a
diagram for explaining electrical couplings of the drive IC 62, the
wiring substrate 38, the actuator substrate 36, and the
piezoelectric elements 60.
[0079] The actuator substrate 36 is a plate-shaped member and can
vibrate. On an upper surface of the actuator substrate 36 in the Z
direction, a plurality of piezoelectric elements 60 are arranged in
two lines in the Y direction as shown in FIG. 3. In each
piezoelectric element 60, a lower electrode layer 137, a
piezoelectric layer 138, and an upper electrode layer 139 are
sequentially stacked along the Z direction on an upper surface of
the actuator substrate 36. The piezoelectric layer 138 is displaced
in accordance with an electric potential difference generated
between the lower electrode layer 137 and the upper electrode layer
139 of the piezoelectric element 60 configured as described above,
and the actuator substrate 36 is deformed in the Z direction in
accordance with the displacement of the piezoelectric layer
138.
[0080] In FIG. 6, the lower electrode layer 137 is an individual
electrode that supplies the drive signal VOUT to each piezoelectric
element 60, and the upper electrode layer 139 is a common electrode
common to supply the reference voltage signal VBS to the plurality
of piezoelectric elements 60. Note that the lower electrode layer
137 may be a common electrode and the upper electrode layer 139 may
be an individual electrode.
[0081] On the upper surface of the actuator substrate 36 in the Z
direction, the wiring substrate 38 is stacked. On the wiring
substrate 38, a plurality of wirings and electrodes for supplying
various signals to the actuator substrate 36 are provided. Details
of the plurality of wirings and electrodes provided on the wiring
substrate 38 will be described later.
[0082] On the surface G1 of the wiring substrate 38, bump
electrodes 141 and 142 for supplying the drive signal VOUT output
from the drive IC 62 to the corresponding piezoelectric element 60
are provided. The bump electrode 141 is provided inside the
plurality of piezoelectric elements 60 arranged in two lines, for
example, at a position corresponding to the lower electrode layer
137 of the piezoelectric element 60 corresponding to the nozzle N1
included in the line L1 shown in FIG. 3. The bump electrode 141 and
the lower electrode layer 137 are electrically coupled to each
other, whereby the drive signal VOUT is supplied to the
piezoelectric element 60. Further, the bump electrode 141 is also
electrically coupled to an electrode 151 formed on the surface G1
of the wiring substrate 38.
[0083] The bump electrode 142 is provided inside the plurality of
piezoelectric elements 60 arranged in two lines, for example, at a
position corresponding to the lower electrode layer 137 of the
piezoelectric element 60 corresponding to the nozzle N2 included in
the line L2 shown in FIG. 3. The bump electrode 142 and the lower
electrode layer 137 are electrically coupled to each other, whereby
the drive signal VOUT is supplied to the piezoelectric element 60.
Further, the bump electrode 142 is also electrically coupled to an
electrode 152 formed on the surface G1 of the wiring substrate
38.
[0084] A bump electrode 143 for supplying the reference voltage
signal VBS to the piezoelectric element 60 is provided on the
surface G1 of the wiring substrate 38. The bump electrode 143 is
provided at a position corresponding to the upper electrode layer
139 of the piezoelectric element 60. The bump electrode 143 and the
upper electrode layer 139 are electrically coupled to each other,
whereby the reference voltage signal VBS is supplied to the
piezoelectric element 60. Further, the bump electrode 143 is also
electrically coupled to an electrode 153 formed on the surface G1
of the wiring substrate 38.
[0085] On the surface G1 of the wiring substrate 38, wirings 510 to
512 and 517 to 519 extending along the Y direction are formed along
the X axis. Specifically, the wirings 510 to 512 are arranged in
the order of the wirings 510, 511, and 512 in a direction from the
electrode 151 toward the electrode 153 between the electrode 151
and the electrode 153. Further, the wirings 517 to 519 are arranged
in the order of the wirings 517, 518, and 519 in a direction from
the electrode 153 toward the electrode 152 between the electrode
153 and the electrode 152.
[0086] An electrode 171 corresponding to the electrode 151 is
formed on the surface G2 of the wiring substrate 38 on the side
opposite to the surface G1. The electrode 151 and the electrode 171
are electrically coupled by a through-wiring 173 passing through
the wiring substrate 38.
[0087] An electrode 172 corresponding to the electrode 152 is
formed on the surface G2 of the wiring substrate 38. The electrode
152 and the electrode 172 are electrically coupled by a
through-wiring 174 passing through the wiring substrate 38.
[0088] On the surface G2 of the wiring substrate 38, electrodes 190
to 199 are formed between the electrode 171 and the electrode 172.
Specifically, the electrodes 190 to 199 are arranged in the order
of the electrodes 190, 191, 192, 193, 194, 195, 196, 197, 198, and
199 in a direction from the electrode 171 toward the electrode 172
between the electrode 151 and the electrode 153.
[0089] The drive IC 62 is mounted on the upper surface of the
wiring substrate 38 in the Z direction. A bump electrode 201 is
provided, on a surface of the drive IC 62 facing the wiring
substrate 38 and in a region facing the electrode 171 of the wiring
substrate 38. Further, the bump electrode 201 is also electrically
coupled to an electrode 211 formed on the drive IC 62.
[0090] Similarly, a bump electrode 202 is provided, on a surface of
the drive IC 62 facing the wiring substrate 38 and in a region
facing the electrode 172 of the wiring substrate 38. Further, the
bump electrode 202 is also electrically coupled to an electrode 212
formed on the drive IC 62.
[0091] Bump electrode 220 to 229 are provided, on a surface of the
drive IC 62 facing the wiring substrate 38 and in a region facing
each of the electrodes 190 to 199 of the wiring substrate 38.
Further, each of the bump electrodes 220 to 229 is electrically
coupled to each of the electrodes 230 to 239 formed on the drive IC
62.
[0092] The configuration of the bump electrodes 141 to 143, 201,
202, and 220 to 229 which are electrically coupled to the drive IC
62, the wiring substrate 38 and the actuator substrate 36,
respectively, will be described with reference to FIG. 7. Note that
the bump electrodes 141 to 143, 201, 202, and 220 to 229 have the
same configuration, and in the description of FIG. 7, a bump
electrode 240 will be described.
[0093] FIG. 7 is a diagram showing an example of a configuration of
a bump electrode 240. A top view in FIG. 7 shows a plan view of the
bump electrode 240, and a bottom view in FIG. 7 shows a side view
of the bump electrode 240. The bump electrode 240 is a resin core
bump including a resin core portion 241 protrudingly provided, and
a metal electrode 242 formed on the upper part of the core portion
241. In such a bump electrode 240, a spacing between the bump
electrodes 240 can be reduced since a space between patterns of the
electrodes 242 can be constituted by an insulator core portion
241.
[0094] Note that in the present embodiment, although the bump
electrode 240 is illustrated and described as including the core
portion 241 and the electrode 242 individually, a plurality of bump
electrodes 240 may be formed by forming a plurality of electrodes
242 on an upper part of the core portion 241 provided in
common.
1.5 Configuration of Wiring Substrate
[0095] Details of a plurality of wirings and electrodes provided on
the wiring substrate 38 will be described with reference to FIGS. 8
and 9. FIG. 8 is a plan view showing a configuration when the
wiring substrate 38 is viewed from the surface G2. FIG. 9 is a plan
view showing a configuration when the wiring substrate 38 is viewed
from the surface Gl. In addition, in FIG. 8, the drive ICs 62
mounted on the wiring substrate 38 are indicated by one-dot chain
lines.
[0096] As shown in FIGS. 8 and 9, the wiring substrate 38 includes
a substrate 300.
[0097] The substrate 300 has a substantially rectangular shape
which has a first surface 305 and a second surface 306 opposing the
first surface 305, and which is formed by a side 301 that is an
example of a first side, a side 302 that faces the side 301, a side
303 that is longer than the side 301 and is an example of a second
side, and a side 304 opposite to the side 303. On the substrate
300, a coupling wiring region 65 including a plurality of
electrodes to which the coupling wiring 64 is coupled, a plurality
of wirings, and a plurality of electrodes, are formed. Note that
the first surface 305 of the substrate 300 is a surface having the
same direction as the surface G2 of the wiring substrate 38 and the
second surface 306 of the substrate 300 is a surface having the
same direction as the surface G1 of the wiring substrate 38.
[0098] Electrodes 380 to 389 and 392 to which the coupling wiring
64 is electrically coupled are formed in the coupling wiring region
65.
[0099] As shown in FIG. 8, the electrode 380 is formed on the
wiring 310. The electrode 380 electrically couples the wiring 310
with the coupling wiring 64. The wiring 310 is a wiring pattern
formed along the Y direction from the side 301 toward the side 302
on the first surface 305 of the substrate 300. The drive signal
COMA is supplied to the electrode 380. The wiring 310 propagates
the drive signal COMA input via the electrode 380. Further, an
electrode 190 is formed on the wiring 310. The electrode 190 is
electrically coupled to the bump electrode 220 as shown in FIG. 6.
As a result, the drive signal COMA supplied via the electrode 380
is propagated through the wiring 310 and then supplied to the drive
IC 62 via the bump electrode 220. In the present embodiment, M
number of electrodes 190 are formed on the wiring 310 corresponding
to each of the M number of nozzles N1 forming the line L1. In
addition, M number of bump electrodes 220 are provided
corresponding to the M number of electrodes 190.
[0100] A through-wiring 320 passing through the substrate 300 and
electrically coupled to the wiring 310, is formed on a side closer
to the side 301 than the electrode 380 in the wiring 310. The
through-wiring 320 is electrically coupled to the wiring 310 at a
coupling point 340. Further, a through-wiring 330 passing through
the substrate 300 and electrically coupled to the wiring 310, is
formed on a side closer to the side 302 than the electrode 380 in
the wiring 310. The through-wiring 330 is electrically coupled to
the wiring 310 at a coupling point 350. In other words, the
electrode 380 is positioned between the coupling point 340 and the
coupling point 350 in the wiring 310.
[0101] The through-wiring 320 and the through-wiring 330 are
electrically coupled to the wiring 510 formed on the second surface
306 as shown in FIG. 9. That is, the through-wirings 320 and 330
pass through the substrate 300 and electrically couple the wirings
310 with 510. As a result, the drive signal COMA input via the
electrode 380, is propagated through the wiring 510 via the wiring
310 and the through-wiring 320, and then is supplied to the drive
IC 62 via the through-wiring 330, the wiring 310 and the bump
electrode 220.
[0102] As shown in FIG. 8, the wiring 310 includes a buried wiring
370 buried in the substrate 300 and a surface layer wiring 360
formed so as to cover the buried wiring 370. As described above,
since the wiring 310 through which the drive signal COMA is
propagated includes the buried wiring 370, the size of the wiring
substrate 38 can be reduced, a cross-sectional area of the wiring
310 through which the drive signal COMA is propagated can be
increased, and a wiring resistance of the wiring 310 can be
reduced. Note that the surface layer wiring 360 is formed so as to
cover the buried wiring 370 means that the entire buried wiring 370
may not be necessarily covered with the surface layer wiring 360
and at least a part of the buried wiring 370 may be covered with
the surface layer wiring 360.
[0103] As shown in FIG. 9, the wiring 510 includes a buried wiring
570 buried in the substrate 300 and a surface layer wiring 560
formed so as to cover the buried wiring 570. As described above,
since the wiring 510 through which the drive signal COMA is
propagated includes the buried wiring 570, the size of the wiring
substrate 38 can be reduced, a cross-sectional area of the wiring
510 through which the drive signal COMA is propagated can be
increased, and a wiring resistance of the wiring 510 can be
reduced. Note that the surface layer wiring 560 is formed so as to
cover the buried wiring 570 means that the entire buried wiring 570
may not be necessarily covered with the surface layer wiring 560
and at least a part of the buried wiring 570 may be covered with
the surface layer wiring 560.
[0104] The wiring 310 is an example of a second wiring, the wiring
510 is an example of a third wiring, the through-wiring 320 is an
example of a fourth wiring, and the through-wiring 330 is an
example of a fifth wiring. Further, the coupling point 340 is an
example of a first coupling point, and the coupling point 350 is an
example of a second coupling point. The buried wiring 370 is an
example of a first buried wiring, and the buried wiring 570 is an
example of a second buried wiring.
[0105] As shown in FIG. 8, the electrode 380 may be positioned
between the coupling point 340 and the drive IC 62 in a direction
along the side 304. As a result, the drive signal COMA supplied
from the connection wiring 64 is branched into a path which is
propagated through the wiring 310 and is supplied to the drive IC
62, and a path which is propagated through the wiring 510 and is
supplied to the drive IC 62, immediately after being input to the
electrode 380. Therefore, the current flowing through each of the
wiring 310 and the wiring 510 is reduced. Thus, it is possible to
reduce a heat generation of the wiring substrate 38 caused by a
current based on the propagation of the drive signal COMA, and a
voltage drop of the drive signal COMA.
[0106] As shown in FIG. 8, the electrode 381 is formed on the
wiring 311. The electrode 381 electrically couples the wiring 311
with the coupling wiring 64. The wiring 311 is a wiring pattern
formed along the Y direction from the side 301 toward the side 302
on the side 304 side of the wiring 310 on the first surface 305 of
the substrate 300. The drive signal COMB is supplied to the
electrode 381. The wiring 311 propagates the drive signal COMB
input via the electrode 381. Further, an electrode 191 is formed on
the wiring 311. The electrode 191 is electrically coupled to the
bump electrode 221 as shown in FIG. 6. As a result, the drive
signal COMB supplied via the electrode 381 is propagated through
the wiring 311 and then supplied to the drive IC 62 via the bump
electrode 221. In the present embodiment, M number of electrodes
191 are formed on the wiring 311 corresponding to each of the M
number of nozzles N1 forming the line L1. In addition, M number of
bump electrodes 221 are provided corresponding to the M number of
electrodes 191.
[0107] A through-wiring 321 passing through the substrate 300 and
electrically coupled to the wiring 311, is formed on a side closer
to the side 301 than the electrode 381 in the wiring 311. The
through-wiring 321 is electrically coupled to the wiring 311 at a
coupling point 341. Further, a through-wiring 331 passing through
the substrate 300 and electrically coupled to the wiring 311, is
formed on a side closer to the side 302 than the electrode 381 in
the wiring 311. The through-wiring 331 is electrically coupled to
the wiring 311 at a coupling point 351. In other words, the
electrode 381 is positioned between the coupling point 341 and the
coupling point 351 in the wiring 311.
[0108] The through-wiring 321 and the through-wiring 331 are
electrically coupled to the wiring 511 formed on the second surface
306 as shown in FIG. 9. That is, the through-wirings 321 and 331
pass through the substrate 300 and electrically couple the wirings
311 with 511. As a result, the drive signal COMB input via the
electrode 381, is propagated through the wiring 511 via the wiring
311 and the through-wiring 321, and then is supplied to the drive
IC 62 via the through-wiring 331, the wiring 311 and the bump
electrode 221.
[0109] As shown in FIG. 8, similarly to the wirings 310, the wiring
311 includes a buried wiring 371 buried in the substrate 300 and a
surface layer wiring 361 formed so as to cover the buried wiring
371. Therefore, the size of the wiring substrate 38 can be reduced,
a cross-sectional area of the wiring 311 through which the drive
signal COMB is propagated can be increased, and thus a wiring
resistance of the wiring 311 can be reduced.
[0110] As shown in FIG. 9, similarly to the wirings 510, the wiring
511 includes a buried wiring 571 buried in the substrate 300 and a
surface layer wiring 561 formed so as to cover the buried wiring
571. Therefore, the size of the wiring substrate 38 can be reduced,
a cross-sectional area of the wiring 511 through which the drive
signal COMB is propagated can be increased, and thus a wiring
resistance of the wiring 511 can be reduced.
[0111] The wiring 311 is another example of the second wiring, the
wiring 511 is another example of the third wiring, the
through-wiring 321 is another example of the fourth wiring, and the
through-wiring 331 is another example of the fifth wiring. Further,
the coupling point 341 is another example of the first coupling
point, and the coupling point 351 is another example of the second
coupling point. The buried wiring 371 is another example of the
first buried wiring, and the buried wiring 571 is another example
of the second buried wiring.
[0112] As shown in FIG. 8, the electrode 381 may be positioned
between the coupling point 341 and the drive IC 62 in a direction
along the side 304. As a result, the drive signal COMB supplied
from the coupling wiring 64 branched into a path which is
propagated through the wiring 311 and is supplied to the drive IC
62, and a path which is propagated through the wiring 511 and is
supplied to the drive IC 62, immediately after being input to the
electrode 381. Therefore, the current flowing through each of the
wiring 311 and the wiring 511 is reduced. Thus, it is possible to
reduce a heat generation of the wiring substrate 38 caused by a
current based on the propagation of the drive signal COMB, and a
voltage drop of the drive signal COMB.
[0113] As shown in FIG. 8, the electrode 382 is formed on the
wiring 312. The electrode 382 electrically couples the wiring 312
with the coupling wiring 64. The wiring 312 is a wiring pattern
formed along the Y direction extending from the side 301 toward the
side 302 on the first surface 305 of the substrate 300 and on the
side of the side 304 of the wiring 311. The high voltage signal VHV
is supplied to the electrode 382. The wiring 312 propagates the
high voltage signal VHV input via the electrode 382. Further, an
electrode 192 is formed on the wiring 312. The electrode 192 is
electrically coupled to the bump electrode 222 as shown in FIG. 6.
As a result, the high voltage signal VHV supplied via the electrode
382 is propagated through the wiring 312 and then supplied to the
drive IC 62 via the bump electrode 222. In the present embodiment,
M number of electrodes 192 are formed on the wiring 312
corresponding to each of the M number of nozzles N1 or nozzles N2
forming the line L1 or the line L2. In addition, M number of bump
electrodes 222 are provided corresponding to the M number of
electrodes 192. The electrode 192 and the bump electrode 222 for
supplying the high voltage signal VHV to the drive IC 62 may not be
provided corresponding to the M number of nozzles N1 or nozzles N2,
for example, the high voltage signal VHV may be supplied to the
drive IC 62 via one electrode 192 and one bump electrode 222.
[0114] A through-wiring 322 passing through the substrate 300 and
electrically coupled to the wiring 312, is formed on a side closer
to the side 301 than the electrode 382 in the wiring 312. The
through-wiring 322 is electrically coupled to the wiring 312 at a
coupling point 342. Further, a through-wiring 332 passing through
the substrate 300 and electrically coupled to the wiring 312, is
formed on a side closer to the side 302 than the electrode 382 in
the wiring 312. The through-wiring 332 is electrically coupled to
the wiring 312 at a coupling point 352. In other words, the
electrode 382 is positioned between the coupling point 342 and the
coupling point 352 in the wiring 312.
[0115] The through-wiring 322 and the through-wiring 332 are
electrically coupled to the wiring 512 formed on the second surface
306 as shown in FIG. 9. That is, the through-wirings 322 and 332
pass through the substrate 300 and electrically couple the wirings
312 with 512. As a result, the high voltage signal VHV input via
the electrode 382, is propagated through the wiring 512 via the
wiring 312 and the through-wiring 322, and then is supplied to the
drive IC 62 via the through-wiring 332, the wiring 312 and the bump
electrode 222.
[0116] As shown in FIG. 8, similarly to the wirings 310, the wiring
312 includes a buried wiring 372 buried in the substrate 300 and a
surface layer wiring 362 formed so as to cover the buried wiring
372. Therefore, the size of the wiring substrate 38 can be reduced,
a cross-sectional area of the wiring 312 through which the high
voltage signal VHV is propagated can be increased, and thus a
wiring resistance of the wiring 312 can be reduced.
[0117] As shown in FIG. 9, similarly to the wirings 510, the wiring
512 includes a buried wiring 572 buried in the substrate 300 and a
surface layer wiring 562 formed so as to cover the buried wiring
572. Therefore, the size of the wiring substrate 38 can be reduced,
a cross-sectional area of the wiring 512 through which the high
voltage signal VHV is propagated can be increased, and thus a
wiring resistance of the wiring 512 can be reduced.
[0118] As shown in FIG. 8, the electrode 382 may be positioned
between the coupling point 342 and the drive IC 62 in a direction
along the side 304. As a result, the high voltage signal VHV
supplied from the coupling wiring 64 is branched into a path which
is propagated through the wiring 312 and is supplied to the drive
IC 62, and a path which is propagated through the wiring 512 and is
supplied to the drive IC 62, immediately after being input to the
electrode 382. Therefore, the current flowing through each of the
wiring 312 and the wiring 512 is reduced. Thus, it is possible to
reduce a heat generation of the wiring substrate 38 caused by a
current based on the propagation of the high voltage signal VHV,
and a voltage drop of the high voltage signal VHV.
[0119] As shown in FIG. 8, each of the electrodes 383 to 386 is
formed on each wiring of the wirings 313 to 316. Each of the
electrodes 383 to 386 electrically couples each of the wirings 313
to 316 with the coupling wiring 64. The wiring 313 is a wiring
pattern formed along the Y direction from the side 301 toward the
side 302 on the side 304 side of the wiring 312 on the first
surface 305 of the substrate 300. The wiring 314 is a wiring
pattern formed along the Y direction from the side 301 toward the
side 302 on the side 304 side of the wiring 313 on the first
surface 305 of the substrate 300. The wiring 315 is a wiring
pattern formed along the Y direction from the side 301 toward the
side 302 on the side 304 side of the wiring 314 on the first
surface 305 of the substrate 300. The wiring 316 is a wiring
pattern formed along the Y direction from the side 301 toward the
side 302 on the side 304 side of the wiring 315 on the first
surface 305 of the substrate 300. Each of the wirings 313 to 316
propagates the printing data signal SI, the change signal CH, the
latch signal LAT and the clock signal SCK which are input via each
of the electrodes 383 to 386.
[0120] Each of electrodes 193 to 196 is formed on each wiring of
the wirings 313 to 316. Each of the electrodes 193 to 196 is
electrically coupled to each of the bump electrodes 223 to 226 as
shown in FIG. 6. As a result, the printing data signal SI, the
change signal CH, the latch signal LAT, and the clock signal SCK
are supplied to the drive IC 62. In the present embodiment, each of
the electrodes 193 to 196 is formed by M number of electrodes along
the Y direction corresponding to the M number of nozzles N1 or
nozzles N2 forming the line L1 or L2. In addition, each of the bump
electrodes 223 to 226 is formed by M number of bump electrodes
corresponding to each of the electrodes 193 to 196.
[0121] As shown in FIG. 8, the electrode 387 is formed on the
wiring 317. The electrode 387 electrically couples the wiring 317
with the coupling wiring 64. The wiring 317 is a wiring pattern
formed along the Y direction from the side 301 toward the side 302
on the side 304 side of the wiring 316 on the first surface 305 of
the substrate 300. The low voltage signal VDD is supplied to the
electrode 387. The wiring 317 propagates the low voltage signal VDD
input via the electrode 387. Further, an electrode 197 is formed on
the wiring 317. The electrode 197 is electrically coupled to the
bump electrode 227 as shown in FIG. 6. As a result, the low voltage
signal VDD supplied via the electrode 387 is propagated through the
wiring 317 and then supplied to the drive IC 62 via the bump
electrode 227. In the present embodiment, M number of electrodes
197 are formed on the wiring 317 corresponding to each of the M
number of nozzles N1 or nozzles N2 forming the line L1 or the line
L2. In addition, M number of bump electrodes 227 are provided
corresponding to the M number of electrodes 197. The electrode 197
and the bump electrode 227 for supplying the low voltage signal VDD
to the drive IC 62 may not be provided corresponding to the M
number of nozzles N1 or nozzles N2, for example, the low voltage
signal VDD may be supplied to the drive IC 62 via one electrode 197
and one bump electrode 227.
[0122] A through-wiring 327 passing through the substrate 300 and
electrically coupled to the wiring 317, is formed on a side closer
to the side 301 than the electrode 387 in the wiring 317. The
through-wiring 327 is electrically coupled to the wiring 317 at a
coupling point 347. Further, a through-wiring 337 passing through
the substrate 300 and electrically coupled to the wiring 317, is
formed on a side closer to the side 302 than the electrode 387 in
the wiring 317. The through-wiring 337 is electrically coupled to
the wiring 317 at a coupling point 357. In other words, the
electrode 387 is positioned between the coupling point 347 and the
coupling point 357 in the wiring 317.
[0123] The through-wiring 327 and the through-wiring 337 are
electrically coupled to the wiring 517 formed on the second surface
306 as shown in FIG. 9. That is, the through-wirings 327 and 337
pass through the substrate 300 and electrically couple the wirings
317 with 517. As a result, the low voltage signal VDD input via the
electrode 387, is propagated through the wiring 517 via the wiring
317 and the through-wiring 327, and then is supplied to the drive
IC 62 via the through-wiring 337, the wiring 317 and the bump
electrode 227.
[0124] As shown in FIG. 8, similarly to the wirings 310, the wiring
317 includes a buried wiring 377 buried in the substrate 300 and a
surface layer wiring 367 formed so as to cover the buried wiring
377. Therefore, the size of the wiring substrate 38 can be reduced,
a cross-sectional area of the wiring 317 through which the low
voltage signal VDD is propagated can be increased, and thus a
wiring resistance of the wiring 317 can be reduced.
[0125] As shown in FIG. 9, similarly to the wirings 510, the wiring
517 includes a buried wiring 577 buried in the substrate 300 and a
surface layer wiring 567 formed so as to cover the buried wiring
577. Therefore, the size of the wiring substrate 38 can be reduced,
a cross-sectional area of the wiring 517 through which the low
voltage signal VDD is propagated can be increased, and thus a
wiring resistance of the wiring 517 can be reduced.
[0126] As shown in FIG. 8, the electrode 387 may be positioned
between the coupling point 347 and the drive IC 62 in a direction
along the side 304. As a result, the low voltage signal VDD
supplied from the coupling wiring 64 is branched into a path which
is propagated through the wiring 317 and is supplied to the drive
IC 62, and a path which is propagated through the wiring 517 and is
supplied to the drive IC 62, immediately after being input to the
electrode 387. Therefore, the current flowing through each of the
wiring 317 and the wiring 517 is reduced. Thus, it is possible to
reduce a heat generation of the wiring substrate 38 caused by a
current based on the propagation of the low voltage signal VDD, and
a voltage drop of the low voltage signal VDD.
[0127] As shown in FIG. 8, the electrode 388 is formed on the
wiring 318. The electrode 388 electrically couples the wiring 318
with the coupling wiring 64. The wiring 318 is a wiring pattern
formed along the Y direction from the side 301 toward the side 302
on the side 304 side of the wiring 317 on the first surface 305 of
the substrate 300. The drive signal COMB is supplied to the
electrode 388. The wiring 318 propagates the drive signal COMB
input via the electrode 388. Further, an electrode 198 is formed on
the wiring 318. The electrode 198 is electrically coupled to the
bump electrode 228 as shown in FIG. 6. As a result, the drive
signal COMB supplied via the electrode 388 is propagated through
the wiring 318 and then supplied to the drive IC 62 via the bump
electrode 228. In the present embodiment, M number of electrodes
198 are formed on the wiring 318 corresponding to each of the M
number of nozzles N2 forming the line L2. In addition, M number of
bump electrodes 228 are provided corresponding to the M number of
electrodes 198.
[0128] A through-wiring 328 passing through the substrate 300 and
electrically coupled to the wiring 318, is formed on a side closer
to the side 301 than the electrode 388 in the wiring 318. The
through-wiring 328 is electrically coupled to the wiring 318 at a
coupling point 348. Further, a through-wiring 338 passing through
the substrate 300 and electrically coupled to the wiring 318, is
formed on a side closer to the side 302 than the electrode 388 in
the wiring 318. The through-wiring 338 is electrically coupled to
the wiring 318 at a coupling point 358. In other words, the
electrode 388 is positioned between the coupling point 348 and the
coupling point 358 in the wiring 318.
[0129] The through-wiring 328 and the through-wiring 338 are
electrically coupled to the wiring 518 formed on the second surface
306 as shown in FIG. 9. That is, the through-wirings 328 and 338
pass through the substrate 300 and electrically couple the wirings
318 with 518. As a result, the drive signal COMB input via the
electrode 388, is propagated through the wiring 518 via the wiring
318 and the through-wiring 328, and then is supplied to the drive
IC 62 via the through-wiring 338, the wiring 318 and the bump
electrode 228.
[0130] As shown in FIG. 8, similarly to the wirings 310, the wiring
318 includes a buried wiring 378 buried in the substrate 300 and a
surface layer wiring 368 formed so as to cover the buried wiring
378. Therefore, the size of the wiring substrate 38 can be reduced,
a cross-sectional area of the wiring 318 through which the drive
signal COMB is propagated can be increased, and thus a wiring
resistance of the wiring 318 can be reduced.
[0131] As shown in FIG. 9, similarly to the wirings 510, the wiring
518 includes a buried wiring 578 buried in the substrate 300 and a
surface layer wiring 568 formed so as to cover the buried wiring
578. Therefore, the size of the wiring substrate 38 can be reduced,
a cross-sectional area of the wiring 518 through which the drive
signal COMB is propagated can be increased, and thus a wiring
resistance of the wiring 518 can be reduced.
[0132] The wiring 318 is another example of the second wiring, the
wiring 518 is another example of the third wiring, the
through-wiring 328 is another example of the fourth wiring, and the
through-wiring 338 is another example of the fifth wiring. Further,
the coupling point 348 is another example of the first coupling
point, and the coupling point 358 is another example of the second
coupling point. The buried wiring 378 is another example of the
first buried wiring, and the buried wiring 578 is another example
of the second buried wiring.
[0133] As shown in FIG. 8, the electrode 388 may be positioned
between the coupling point 348 and the drive IC 62 in a direction
along the side 304. As a result, the drive signal COMB supplied
from the coupling wiring 64 branched into a path which is
propagated through the wiring 318 and is supplied to the drive IC
62, and a path which is propagated through the wiring 518 and is
supplied to the drive IC 62, immediately after being input to the
electrode 388. Therefore, the current flowing through each of the
wiring 318 and the wiring 518 is reduced. Thus, it is possible to
reduce a heat generation of the wiring substrate 38 caused by a
current based on the propagation of the drive signal COMB, and a
voltage drop of the drive signal COMB.
[0134] As shown in FIG. 8, the electrode 389 is formed on the
wiring 319. The electrode 380 electrically couples the wiring 310
with the coupling wiring 64. The wiring 319 is a wiring pattern
formed along the Y direction from the side 301 toward the side 302
on the side 304 side of the wiring 318 on the first surface 305 of
the substrate 300. The drive signal COMA is supplied to the
electrode 389. The wiring 319 propagates the drive signal COMA
input via the electrode 389. Further, an electrode 199 is formed on
the wiring 319. The electrode 199 is electrically coupled to the
bump electrode 229 as shown in FIG. 6. As a result, the drive
signal COMA supplied via the electrode 389 is propagated through
the wiring 319 and then supplied to the drive IC 62 via the bump
electrode 229. In the present embodiment, M number of electrodes
199 are formed on the wiring 319 corresponding to each of the M
number of nozzles N2 forming the line L2. In addition, M number of
bump electrodes 229 are provided corresponding to the M number of
electrodes 199.
[0135] A through-wiring 329 passing through the substrate 300 and
electrically coupled to the wiring 319, is formed on a side closer
to the side 301 than the electrode 389 in the wiring 319. The
through-wiring 329 is electrically coupled to the wiring 319 at a
coupling point 349. Further, a through-wiring 339 passing through
the substrate 300 and electrically coupled to the wiring 319, is
formed on a side closer to the side 302 than the electrode 389 in
the wiring 319. The through-wiring 339 is electrically coupled to
the wiring 319 at a coupling point 359. In other words, the
electrode 389 is positioned between the coupling point 349 and the
coupling point 359 in the wiring 319.
[0136] The through-wiring 329 and the through-wiring 339 are
electrically coupled to the wiring 519 formed on the second surface
306 as shown in FIG. 9. That is, the through-wirings 329 and 339
pass through the substrate 300 and electrically couple the wirings
319 with 519. As a result, the drive signal COMA input via the
electrode 389, is propagated through the wiring 519 via the wiring
319 and the through-wiring 329, and then is supplied to the drive
IC 62 via the through-wiring 339, the wiring 319 and the bump
electrode 229.
[0137] As shown in FIG. 8, the wiring 318 includes a buried wiring
379 buried in the substrate 300 and a surface layer wiring 369
formed so as to cover the buried wiring 379. As described above,
since the wiring 319 through which the drive signal COMA is
propagated includes the buried wiring 379, the size of the wiring
substrate 38 can be reduced, a cross-sectional area of the wiring
319 through which the drive signal COMA is propagated can be
increased, and a wiring resistance of the wiring 319 can be
reduced.
[0138] Similarly, as shown in FIG. 9, the wiring 519 includes a
buried wiring 579 buried in the substrate 300 and a surface layer
wiring 569 formed so as to cover the buried wiring 579. As
described above, since the wiring 519 through which the drive
signal COMA is propagated includes the buried wiring 579, the size
of the wiring substrate 38 can be reduced, a cross-sectional area
of the wiring 519 through which the drive signal COMA is propagated
can be increased, and a wiring resistance of the wiring 519 can be
reduced.
[0139] The wiring 319 is another example of the second wiring, the
wiring 519 is another example of the third wiring, the
through-wiring 329 is another example of the fourth wiring, and the
through-wiring 339 is another example of the fifth wiring. Further,
the coupling point 349 is another example of the first coupling
point, and the coupling point 359 is another example of the second
coupling point. The buried wiring 379 is an example of a first
buried wiring, and the buried wiring 579 is an example of a second
buried wiring.
[0140] As shown in FIG. 8, the electrode 389 may be positioned
between the coupling point 349 and the drive IC 62 in a direction
along the side 304. As a result, the drive signal COMA supplied
from the connection wiring 64 is branched into a path which is
propagated through the wiring 319 and is supplied to the drive IC
62, and a path which is propagated through the wiring 519 and is
supplied to the drive IC 62, immediately after being input to the
electrode 389. Therefore, the current flowing through each of the
wiring 319 and the wiring 519 is reduced. Thus, it is possible to
reduce a heat generation of the wiring substrate 38 caused by a
current based on the propagation of the drive signal COMA, and a
voltage drop of the drive signal COMA.
[0141] As shown in FIG. 8, the electrode 392 is formed on the
wiring 390. The electrode 392 electrically couples the wiring 390
with the coupling wiring 64. The wiring 390 is formed between the
wiring 314 and the wiring 315 which are formed on the first surface
305 of the substrate 300, and is formed on a side of the side 301.
The reference voltage signal VBS is supplied to the electrode 392.
A through-wiring 391 passing through the substrate 300 and
electrically coupled to the wiring 390, is formed on a side closer
to the side 301 than the electrode 392 in the wiring 390. The
through-wiring 391 is electrically coupled to the wiring 390 at a
coupling point 393.
[0142] The through-wiring 391 is electrically coupled to the wiring
590 formed on the second surface 306 as shown in FIG. 9. That is,
the through-wiring 391 passes through the substrate 300 and
electrically couples the wirings 319 with 519. As a result, the
reference voltage signal VBS input via the electrode 392 is
propagated through the wiring 590 via the wiring 390 and the
through-wiring 391.
[0143] An electrode 153 is formed on the wiring 590. In addition, a
bump electrode 143 is provided on the electrode 153. As shown in
FIG. 6, the bump electrode 143 is electrically coupled to an upper
electrode layer 139 of the piezoelectric element 60 provided on the
actuator substrate 36. As a result, the reference voltage signal
VBS propagated through the wiring 590 is supplied to the
piezoelectric element 60. In the present embodiment, M number of
electrodes 153 are formed on the wiring 590 corresponding to each
of the M number of nozzles N1 or nozzles N2 forming the line L1 or
the line L2. In addition, M number of bump electrodes 143 are
provided corresponding to the M number of electrodes 153.
[0144] As shown in FIG. 9, the wiring 590 includes a buried wiring
592 buried in the substrate 300 and a surface layer wiring 591
formed so as to cover the buried wiring 592. As described above,
since the wiring 590 through which the reference voltage signal VBS
is propagated includes the buried wiring 592, the size of the
wiring substrate 38 can be reduced, a cross-sectional area of the
wiring 590 through which the reference voltage signal VBS is
propagated can be increased, and a wiring resistance of the wiring
590 can be reduced.
[0145] As shown in FIG. 8, an electrode 171 is formed on the side
303 side of the wiring 310 on the first surface 305 of the
substrate 300. The drive signal VOUT supplied from the drive IC 62
to the piezoelectric element 60 corresponding to the nozzle N1 is
output to the electrode 171. Further, a through-wiring 173 passing
through the substrate 300 and electrically coupled to the electrode
171, is formed on a side 303 side of the electrode 171. As shown in
FIG. 9, the through-wiring 173 is electrically coupled to the
electrode 151 on the second surface 306. In addition, a bump
electrode 141 is provided on the electrode 151.
[0146] As shown in FIG. 6, the bump electrode 141 is electrically
coupled to a lower electrode layer 137 of the piezoelectric element
60 corresponding to the nozzle N1 provided on the actuator
substrate 36. As a result, the drive signal VOUT is supplied to the
piezoelectric element 60. In the present embodiment, M number of
electrodes 151 are formed along the Y direction corresponding to
each of the M number of nozzles N1 forming the line L1. In
addition, M number of bump electrodes 141 are provided
corresponding to the M number of electrodes 151. In addition, the
electrode 171 and the through-wiring 173 which are electrically
coupled to the electrode 151 are also formed by M pieces along the
Y direction.
[0147] As shown in FIG. 8, an electrode 172 is formed on the side
304 side of the wiring 319 on the first surface 305 of the
substrate 300. The drive signal VOUT supplied from the drive IC 62
to the piezoelectric element 60 corresponding to the nozzle N2 is
output to the electrode 172. Further, a through-wiring 174 passing
through the substrate 300 and electrically coupled to the electrode
172, is formed on a side 304 side of the electrode 172. As shown in
FIG. 9, the through-wiring 174 is electrically coupled to the
electrode 152 on the second surface 306. In addition, a bump
electrode 142 is provided on the electrode 152.
[0148] As shown in FIG. 6, the bump electrode 142 is electrically
coupled to a lower electrode layer 137 of the piezoelectric element
60 corresponding to the nozzle N1 provided on the actuator
substrate 36. As a result, the drive signal VOUT is supplied to the
piezoelectric element 60. In the present embodiment, M number of
electrodes 152 are formed along the Y direction corresponding to
each of the M number of nozzles N2 forming the line L2. In
addition, M number of bump electrodes 142 are provided
corresponding to the M number of electrodes 152. In addition, the
electrode 172 and the through-wiring 174 which are electrically
coupled to the electrode 152 are also formed by M pieces along the
Y direction.
1.6 Operational Effect
[0149] As described above, in the liquid discharge head 21 included
in the liquid discharge apparatus 1 according to the present
embodiment, both the wiring 310 formed on the first surface 305 and
the wiring 510 formed on the second surface 306 of the substrate
300 propagate the drive signal COMA in the wiring substrate 38. In
this case, the electrode 380 to which the drive signal COMA is
supplied is electrically couples the wiring 310 with the wiring 510
in the wiring 310, and is provided between the through-wiring 320
and the through-wiring 330. As a result, a current generated based
on the drive signal COMA supplied to the electrode 380 is branched
into a path which is propagated through the wiring 310 and is
supplied to the drive IC 62, and a path which is propagated through
the through-wiring 320, the wiring 510 and the through-wiring 330
and is supplied to the drive IC, immediately after being supplied
to the electrode 380. Therefore, the current flowing through each
of the wiring 310 and the wiring 510 that propagate drive signal
COMA, is reduced. Thus, it is possible to reduce a heat generation
of the wiring substrate 38 caused by a current based on the
propagation of the drive signal COMA, and a voltage drop of the
drive signal COMA.
[0150] Note that the same effect can be obtained for each of the
wiring 311 and the wiring 511 that propagate the drive signal COMB
supplied to the piezoelectric element 60 provided on the line L1,
the wiring 319 and the wiring 519 that propagate the drive signal
COMA supplied to the piezoelectric element 60 provided on the line
L2, and the wiring 318 and the wiring 518 that propagate the drive
signal COMB supplied to the piezoelectric element 60 provided on
the line L2.
[0151] Further, the same effect can be obtained for each of the
wiring 312 and the wiring 512 that propagate the high voltage
signal VHV supplied to the drive IC 62, and the wiring 317 and the
wiring 517 that propagate the low voltage signal VDD.
[0152] Further, in the liquid discharge head 21 included in the
liquid discharge apparatus 1 according to the present embodiment,
since it is possible to reduce the amount of current flowing
through the wirings that propagate each of the drive signals COMA
and COMB, the high voltage signal VHV, and the low voltage signal
VDD in the wiring substrate 38, the heat generation of the wiring
substrate 38 caused by a current based on the propagation of each
of the drive signals COMA and COMB, the high voltage signal VHV,
and the low voltage signal VDD, and the voltage drop of the drive
signal COMA can be reduced by providing 600 or more nozzles N in
the liquid discharge head 21 even when there is a possibility that
the propagated currents increase.
2 Second Embodiment
[0153] Next, a liquid discharge apparatus 1, a liquid discharge
head 21 and a wiring substrate 38 of a second embodiment will be
described. In describing the liquid discharge apparatus 1 of the
second embodiment, the same reference numerals are given to the
same configurations as those of the first embodiment, and the
description thereof will be omitted.
[0154] FIGS. 10 and 11 are diagrams for explaining details of a
plurality of wirings and electrodes provided on the wiring
substrate 38 of the second embodiment. FIG. 10 is a plan view
showing a configuration when the wiring substrate 38 is viewed from
the surface G2. FIG. 11 is a plan view showing a configuration when
the wiring substrate 38 is viewed from the surface G1. In addition,
in FIG. 10, the drive ICs 62 mounted on the wiring substrate 38 are
indicated by one-dot chain lines. Further, in FIG. 11, the coupling
wiring region 65 to which the coupling wiring 64 is coupled is
indicated by a two-dot chain line on the first surface of the
substrate 300 included in the wiring substrate 38.
[0155] As shown in FIG. 10, the buried wiring 370 is electrically
coupled to the through-wiring 320. The buried wiring 370 is also
electrically coupled to the through-wiring 330. When viewed from
the first surface 305, the buried wiring 370 is provided at a
position where a part of buried wiring 370 overlaps with the
electrode 380 included in the coupling wiring region 65. The buried
wiring 371 is also electrically coupled to the through-wiring 321.
The buried wiring 371 is also electrically coupled to the
through-wiring 331. When viewed from the first surface 305, the
buried wiring 371 is provided at a position where a part of buried
wiring 370 overlaps with the electrode 381 included in the coupling
wiring region 65. The buried wiring 378 is electrically coupled to
the through-wiring 328. The buried wiring 378 is also electrically
coupled to the through-wiring 338. When viewed from the first
surface 305, the buried wiring 378 is provided at a position where
a part of buried wiring 370 overlaps with the electrode 388
included in the coupling wiring region 65. The buried wiring 379 is
electrically coupled to the through-wiring 329. The buried wiring
379 is also electrically coupled to the through-wiring 339. When
viewed from the first surface 305, the buried wiring 379 is
provided at a position where a part of buried wiring 370 overlaps
with the electrode 389 included in the coupling wiring region
65.
[0156] Further, as shown in FIG. 11, the buried wiring 570 is
electrically coupled to the through-wiring 320. The buried wiring
570 is also electrically coupled to the through-wiring 330. When
viewed from the first surface 305, the buried wiring 570 is
provided at a position where a part of buried wiring 570 overlaps
with the electrode 380 included in the coupling wiring region 65.
The buried wiring 571 is electrically coupled to the through-wiring
321. The buried wiring 571 is also electrically coupled to the
through-wiring 331. When viewed from the first surface 305, the
buried wiring 571 is provided at a position where a part of buried
wiring 571 overlaps with the electrode 381 included in the coupling
wiring region 65. The buried wiring 578 is electrically coupled to
the through-wiring 328. The buried wiring 578 is also electrically
coupled to the through-wiring 338. When viewed from the first
surface 305, the buried wiring 578 is provided at a position where
a part of buried wiring 578 overlaps with the electrode 388
included in the coupling wiring region 65. The buried wiring 579 is
electrically coupled to the through-wiring 329. The buried wiring
579 is also electrically coupled to the through-wiring 339. When
viewed from the first surface 305, the buried wiring 579 is
provided at a position where a part of buried wiring 579 overlaps
with the electrode 389 included in the coupling wiring region
65.
[0157] As described above, the buried wirings 370, 371, 378, and
379 formed on the first surface of the substrate 300 are provided
at positions overlapping with the coupling wiring region 65 when
viewed from the first surface, and further, the buried wirings 570,
571, 578, and 579 formed on the second surface are provided at
positions overlapping with the coupling wiring region 65 when
viewed from the first surface. As a result, it is possible to
further reduce the wiring resistance of the wirings 310, 311, 318,
319, 510, 511, 518, and 519 to be propagated to the drive IC by the
drive signals COMA and COMB supplied from the coupling wiring 64.
Thus, it is possible to reduce a heat generation of the wiring
substrate 38 caused by a current based on the propagation of each
of the drive signals COMA and COMB, and voltage drops of the drive
signals COMA and COMB.
3 Third Embodiment
[0158] Next, a liquid discharge apparatus 1, a liquid discharge
head 21 and a wiring substrate 38 of a third embodiment will be
described. In describing the liquid discharge apparatus 1 of the
third embodiment, the same reference numerals are given to the same
configurations as those of the first embodiment and the second
embodiment, and the description thereof will be omitted.
[0159] FIGS. 12 and 13 are diagrams for explaining details of a
plurality of wirings and electrodes provided on the wiring
substrate 38 of the third embodiment. FIG. 12 is a plan view
showing a configuration when the wiring substrate 38 is viewed from
the surface G2. FIG. 13 is a plan view showing a configuration when
the wiring substrate 38 is viewed from the surface G1. In addition,
in FIG. 12, the drive ICs 62 mounted on the wiring substrate 38 are
indicated by one-dot chain lines.
[0160] As shown in FIG. 12, a through-wiring 430 passing through
the substrate 300 and electrically coupled to the wiring 310, is
formed between the electrode 380 and the coupling point 350 in the
wiring 310. The through-wiring 430 is electrically coupled to the
wiring 310 at a coupling point 450. That is, the coupling point 450
is positioned between the electrode 380 and the coupling point 450
in the wiring 310. The through-wiring 430 is electrically coupled
to the wiring 510 as shown in FIG. 13.
[0161] A wiring length of the path, through which the drive signal
COMA supplied to the electrode 380 is propagated through the wiring
310 and is supplied to the drive IC 62, is different from a wiring
length of a path, through which the drive signal COMA supplied to
the electrode 380 is propagated through the wiring 510 and is
supplied to the drive IC 62. Therefore, there is a possibility that
the voltage of the drive signal COMA propagated through the wiring
310 and the voltage of the drive signal COMA propagated through the
wiring 510 vary.
[0162] As shown in FIG. 12 and FIG. 13, variations in voltage
between the drive signal COMA propagated through the wiring 310 and
the drive signal COMA propagated through the wiring 510 are reduced
by forming the through-wiring 430 between the electrode 380 and the
coupling point 350 in the wiring 310.
[0163] As shown in the FIG. 12, a through-wiring 431 passing
through the substrate 300 and electrically coupled to the wiring
311, is formed between the electrode 381 and the coupling point 351
in the wiring 311. The through-wiring 431 is electrically coupled
to the wiring 311 at a coupling point 451. That is, the coupling
point 451 is positioned between the electrode 381 and the coupling
point 451 in the wiring 311. The through-wiring 431 is electrically
coupled to the wiring 511 as shown in FIG. 13.
[0164] As described above, variations in voltage between the drive
signal COMB propagated through the wiring 311 and the drive signal
COMB propagated through the wiring 511 are reduced by forming the
through-wiring 431 between the electrode 381 and the coupling point
351 in the wiring 311.
[0165] As shown in the FIG. 12, a through-wiring 438 passing
through the substrate 300 and electrically coupled to the wiring
318, is formed between the electrode 388 and the coupling point 358
in the wiring 318. The through-wiring 438 is electrically coupled
to the wiring 318 at a coupling point 458. That is, the coupling
point 458 is positioned between the electrode 388 and the coupling
point 458 in the wiring 318. The through-wiring 438 is electrically
coupled to the wiring 518 as shown in FIG. 13.
[0166] As described above, variations in voltage between the drive
signal COMB propagated through the wiring 318 and the drive signal
COMB propagated through the wiring 518 are reduced by forming the
through-wiring 438 between the electrode 388 and the coupling point
358 in the wiring 318.
[0167] As shown in the FIG. 12, a through-wiring 439 passing
through the substrate 300 and electrically coupled to the wiring
319, is formed between the electrode 389 and the coupling point 359
in the wiring 319. The through-wiring 439 is electrically coupled
to the wiring 319 at a coupling point 459. That is, the coupling
point 459 is positioned between the electrode 389 and the coupling
point 459 in the wiring 319. The through-wiring 439 is electrically
coupled to the wiring 519 as shown in FIG. 13.
[0168] As described above, variations in voltage between the drive
signal COMA propagated through the wiring 319 and the drive signal
COMA propagated through the wiring 519 are reduced by forming the
through-wiring 439 between the electrode 389 and the coupling point
359 in the wiring 319.
[0169] Therefore, in the liquid discharge apparatus 1, the liquid
discharge head 21, and the wiring substrate 38 in the third
embodiment, in addition to the effects described in the first
embodiment and the second embodiment, it is possible to reduce
variations in voltage generated in the drive signals COMA and
COMB.
[0170] Here, one of the through-wirings 430, 431, 438, and 439 is
an example of a sixth wiring, and one of the coupling points 450,
451, 458, and 459 is an example of a third coupling point.
4 Fourth Embodiment
[0171] Next, a liquid discharge apparatus 1, a liquid discharge
head 21 and a wiring substrate 38 of a fourth embodiment will be
described. In describing the liquid discharge apparatus 1 of the
fourth embodiment, the same reference numerals are given to the
same configurations as those of the first embodiment, the second
embodiment, and the third embodiment, and the description thereof
will be omitted.
[0172] FIGS. 14 and 15 are diagrams for explaining details of a
plurality of wirings and electrodes provided on the wiring
substrate 38 of the fourth embodiment. FIG. 14 is a plan view
showing a configuration when the wiring substrate 38 is viewed from
the surface G2. FIG. 15 is a plan view showing a configuration when
the wiring substrate 38 is viewed from the surface G1. In addition,
in FIG. 14, the drive ICs 62 mounted on the wiring substrate 38 are
indicated by one-dot chain lines.
[0173] As shown in FIG. 14, in the liquid discharge apparatus 1 of
the fourth embodiment, through-wirings 330, 331, 338, and 339
passing through the substrate 300 of the wiring substrate 38 are
positioned between the coupling wiring region 65 and the drive IC
62. A current generated due to the drive signals COMA and COMB
input to the wiring substrate 38 becomes the largest in the
coupling wiring region 65. The current gradually decreases as the
drive signals COMA and COMB are supplied to the drive IC 62 and the
piezoelectric element 60.
[0174] Therefore, as shown in the fourth embodiment, it is possible
to reduce the heat generation and the voltage drop occurring in the
wiring substrate 38 in the coupling wiring region 65 where the
largest current flows by providing the through-wirings 330, 331,
338, and 339 passing through the substrate 300 of the wiring
substrate 38 between the coupling wiring region 65 and the drive IC
62.
[0175] Further, as shown in FIG. 15, since a region where the
wirings 510, 511, 512, 517, 518, and 519 are formed on the second
surface 306 of the substrate 300 can be reduced, it is possible to
miniaturize the wiring substrate by providing a control wiring or
the like in the region. Therefore, in the liquid discharge
apparatus 1, the liquid discharge head 21, and the wiring substrate
38 in the fourth embodiment, in addition to the effects described
in the first embodiment, the wiring substrate 38 can be
miniaturized.
* * * * *